Comparison of genetic diversity between narrowly endemic shrub Menziesia goyozanensis and its widespread congener M. pentandra (Ericaceae)

Menziesia goyozanensis, a Japanese kind of fool's huckleberry, is a shrub species endemic only to Mr. Goyo in northern Japan. This species is listed as 'critically endangered' in the Red Data Book of wild plants in Japan, and only a single population has yet been discovered. The allozyme diversity and RAPD variation of Menziesia pentandra were eight- and threefold greater than those of M. goyozanensis, respectively, although we examined only five populations representing a part of the distribution of M. pentandra. Because the environment surrounding the population of M. goyoznaensis seems to be stable at present, it is not necessary to plan an urgent ecological conservation practice for the species. However, considering that the habitat of M. goyozanensis is very small and large vegetative disturbances occasionally occur in cool temperate forests, in which the species dwells, ex situ conservation is essential.